Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

C14- ALKENES > 14.3- ADDITION POLYMERS > Flashcards

14.3- ADDITION POLYMERS Flashcards

1
Q

What are polymers?

A

very large molecules built-up from small molecules called monomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Examples of naturally occurring polymers? (4)

A

starch
proteins
cellulose
DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What was the first completely synthetic polymer?

A

Bakelite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When was Bakelite patented?

A

1907

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is one way of classifying polymers?

A

by the type of reaction by which they are made

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are addition polymers made from?

A

monomer(s) with a carbon-carbon double bond (alkenes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The monomers that make up polymers are based on what?

A

ethene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens to the double bond in the monomer when it polymerises?

A

double bond opens and monomers bond together to form backbone of carbon atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is phenylethane sometimes called?

A

styrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is poly(phenylethane) sometimes called?

A

polystyrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What must addition polymers have?

A

backbone of carbon atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What must the monomers of addition polymers must contain?

A

at least two carbon atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why must monomers of addition polymers must contain at least two carbon atoms?

A

so that there can be a carbon-carbon double bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can the properties of polymers materials be modified?

A

use of additives i.e. plasticisers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are plasticisers?

A

small molecules than get between the polymer chains forcing them apart + allowing them to slide across each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

e.g. of plasticiser being used (before + after)

A

PVC rigid enough for use as drainpipes, with addition of plasticiser become flexible enough for making aprons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the backbone of a polyalkene?

A

long chain saturated alkane molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How are the bonds in alkanes described to be?

A

strong, non-polar C-C and C-H bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

As the bond in alkenes are strong and non-polar, how reactive are they?

A

very unreactive molecules

20
Q

As alkanes are very unreactive molecules, what cannot be done to them?

A

not attacked by biological agents, like enzymes

21
Q

As alkanes cannot be attacked by biological agents, what are they described as?

A

not biodegradable

22
Q

How is low density poly(ethene) made?

A

made by polymerising ethene at high pressure and high temperature via a free-radical mechanism

23
Q

What does polymerising ethene at high pressure + high temperature via a free-radical mechanism produce?

A

polymer with a certain amount of chain branching

24
Q

What is the chain branching in LDPE due to?

A

consequence of rather random nature of free-radical reactions

25
Q

Are the branched chains in LDPE packed together?

A

not packed together particularly well

26
Q

How flexible is LDPE?

A

quite flexible

27
Q

How well does LDPE stretch?

A

stretches well

28
Q

What is the density of LDPE like?

A

fairly low density

29
Q

What does the properties of LDPE make it suitable for?

A

packaging (plastic bags), sheeting + insulation for electrical cables

30
Q

At what conditions is high density polythene made?

A

temperatures + pressures little greater than room conditions + uses Ziegler-Natta catalyst

31
Q

What does polymerising ethene at temperatures + pressures little greater than room conditions + use of Ziegler-Natta catalyst produce?

A

polymer with much less chain branching than LDPE

32
Q

Can the chain pack together well? (HDPE)

A

yes

33
Q

What is the density of HDPE like In comparison to LDPE?

A

greater

34
Q

What is the melting temperature of HDPE like in comparison to LDPE?

A

higher

35
Q

Typical uses of HDPE? (3)

A

milk crates
buckets
bottles

36
Q

How can the amount of plastic be reduced?

A

by reusing or recycling it

37
Q

What is the simplest form of recycling called?

A

mechanical recycling

38
Q

What is the first step of mechanical recycling?

A

separate the different types of plastics

39
Q

What is the second step of mechanical recycling?

A

plastics washed and once sorted they may be ground up into small pellets

40
Q

What can happen to the small pellets of plastics in mechanical recycling?

A

be melted or remoulded

41
Q

Example of mechanical recycling?

A

recycled soft drinks bottles made from PET used to make fleece clothes

42
Q

What happens in feedstock recycling?

A

plastics heated to temperature that will break the polymer bonds + produce monomers

43
Q

What can the monomers from feedstock recycling be used to do?

A

make new plastics

44
Q

What type of plastic is poly(propene)? (feedstock recycling)

A

thermoplastic polymer

45
Q

What happens to thermoplastic polymers when heated? (feedstock recycling)

A

soften so can be melted and re-used

46
Q

Why can thermoplastics only be heated and re-used only be done a limited number of times?

A

as at each heating some of the chains break and become shorter so degrading the plastic’s properties

C14- ALKENES (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions